Child sexual abuse (CSA) may be defined as severe and/or repeated adverse sexual experience(s) involving genital contact before the age of 18 years by an older perpetrator. The prevalence of sexual abuse in females has been estimated at up to 33% (Peters, Wyatt & Finkelhor, 1988; Whitwell, 1990). The objective of this proposal was to study the psychobiology of chronic traumatic stress in sexually abused girls ages 6 through 12 years. We targeted girls who experienced incidents of sexual fondling at least 3 months, but less than 12 months prior to participation in this study. Sexually abused girls ranged in age from 8.0 to 11. 1 years, with a mean of 9.0 years. Sexually abused girls were either genitally and orally fondled or just genitally fondled. None had experienced penile penetration. All girls experienced multiple abuse episodes. Therefore, this group is most consistent with a chronically stressed rather than an acutely stressed population. Comparison girls were recruited from families known to the investigators who were generally similar in demographic variables. Their ages ranged from 8.0 to 11.4, with a mean of 8.1 years. Post-traumatic stress develops following exposure to intensely distressing events, such as sexual abuse. In the presence of intense stress, endogenous stress-responsive neurohormones including catecholamines, hormones of the hypothalamic-pituitary-adrenal axis, and endogenous opioids are released. The organism utilizes these stress hormones to activate the energy necessary to handle the stressor in various ways, including increased glucose release and heightened arousal. However, the body's adaptation to persistent stress may inhibit the efficacy of the stress response and lead to desensitization. We hypothesized that the posttraumatic stress of sexual abuse causes alterations in the hypothalamic-pituitary-adrenal axis, specifically decreased glucocorticoid levels, which are related to deficits in memory, attention and affective status.